New Year Options

UK - January 13, 2009

Many growers looking to control grassweeds in the crop rotation still have the opportunity to benefit from using Kerb Flo (propyzamide) until 31 January in oilseed rape.

Exceptional weather conditions, reduced applications of pre-emergence herbicides in oilseed rape and the fact that some growers are waiting to see if their crops will be viable, means many growers have postponed making a decision about using Kerb Flo.

However, growers can still gain excellent levels of blackgrass control in winter oilseed rape, even of resistant populations, from January applications. In independent trials, conducted by ADAS, percentage control in the high 90s has been recorded, even where large, well-tillered blackgrass plants are present.

Growers can also benefit from its efficacy in controlling a range of other weeds, particularly resistant ryegrass, wild oats and the increasing problems posed by annual meadow grass, and brome species.

“There are some distinct advantages in using Kerb Flo in these cold conditions,” says Dow AgroSciences technical expert David Roberts. “For instance, field access may be easier and there is reduced compaction. The cold weather and/or pigeon damage will have opened up the crop canopy making it easier for applications of Kerb Flo to reach the soil surface.

“Where ‘frost heave’ occurs, it will cause grassweeds to produce additional adventitious roots near the surface making them more susceptible to Kerb Flo and its residual activity will be enhanced.

“However, there are cautionary notes to treating frosted fields. Spraying when air temperatures are near or below 0°C is associated with the risk of sprays freezing at the nozzle tips. Growers must ensure they follow best practice and should not apply Kerb Flo if run-off is likely. Neither should Kerb Flo be applied if significant rainfall or snow is forecast. Late applications of Kerb Flo means growers should also give particular attention to label recommendations to plough after the rape crop and before establishing following cereal crops.”